Machine for truing toric tools.



J. H. PEARSEN. MACHINE'FOR mums TDRIC TOOLS.

APPLICATION FILED SEPT H). 1917- 1,287,091 Patented Dec. 10, 1918.

3 SHEETS-SHEET 2.

m Y. w E H W w J V a TTDRHEYS J. H. PEARSEN.

MACHINE FOB TRUQNG TORIC TUOLS.

APPLICATION mu) SEPT 10. 19H.

Patented Dec. 10, 1918.

3 SHEETS SHEET 3.

INVENTOE JaH/v finw fmesg/v 13v QQMKMJ +W QTmRNEY-s UNITED STATES PATENT OFFICE.

JOHN HARVEY PEARSEN, OF INDIANAPOLIS, INDIANA. ASSIGNOR TO ONEPIE CE BIFOCAL LENS COMPANY. OF INDIANAPOLIS, INDIANA, A CORPORATION.

MACHINE FOR TRUING TORIC TOOLS.

Specification of Letters Patent.

' Patented Dec. 10, 1918.

Application filed September 10, 1917. Serial No. 190.560.

To all whom it may concern Be it known that I, JOHN HARVEY PEAR- srnv, a citizen of the United States, and a resident of Indianapolis. county of Marion, and State of Indiana, have invented a certain new and useful h'lachine for Truing loric Tools; and I do luzreby declare that he following a full, clear, and exact dcscription thereof, reference being had to the accompanying drawings, in which like letters refer to like parts.

The object of this invention is to provide economical, rapid and convenient means for truing torie tools which are used in the manufacture of toric lenses for eye glass purposes.

a double curved surface, that is, a surface with curvatures in two meridians at right angles to each other. Thus one meridian may have a curvature of eight diopters and the other meridian a curvature of ten diopters, according to the character of the lens desired to he made. Toric tools are made with lathes or like machines for operating upon metal. hen the toric tools have been used somewhat, they wear so that the curvatures cease to be true and accurate. There fore, toric tools must be frequently trued. Hcretofore they have been trued'on lathes or the same kind of machines employed in their manufacture in the first instance. That, however, is a very slow, tedious and expensive method.

The chief feature of the invention herein consists in arranging the machine with an emery wheel having a circumferential curvature of the same curvature as one of the desired meridians of the torio tool, and providing means for holding the hose of the toric tool against the base of the emery wheel and horizontally oscillating it in an arc coinciding with the other meridian of the toxic tool. Therefore, the curvature of the toric tool in one meridian is determined by the circumferential curvature of the emery wheel, while the curvature of the tool in the other meridian is determined by the arc of oscillation of the holder which holds the tool in operative engagement with the emcry wheel and permits its horizontal oscilla'; tion across the face of the emery wheel.

Another feature of the invention consists of graduated means for adjusting the posi- A toric tool is a lens grinding tool having tion of the tool holder so as to change its position with reference 'to the emery wheel and modify the degree of transverse curva ture which the emery wheel would impart to the tool.

With this invention toric tools can he very quickly and cheaply trued. It takes only a very few minutes. This economical means for truing the tool. is possible because the apparatus does not have to generate the surface of the tool and, therefore. has but very little grinding or generating work to do, merely correcting the inequalities in the surface of the tool which have arisen from its use. The amount of change necessary to true the tool makes it unnecessary to take it back to the lathe or other like machine and permits the object to be attained by the use of the simple, quickly and cheaply operated machine herein set forth.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims: V

In the drawings, Figure 1 is a front eleration of the machine, the tool holder heing shown hy dotted lines thrown back in position for inserting a toric tool therein. Fig. 2 is :1 Ian view of the machine, with a portion broxen away and. showing in dotted lines an altered position of the tool holder, and a part of the tool holder being shown in horizontal section on the line 22 of Fig. 1. Fig. 3 is a perspective view of a part of the tool holder, and means for the adjustable mounting thereof, the latter also being shown in vertical section on the line 3-3 of Fig. 1, with the adjusting screw removable. Fig. 4c is a plan view of the grinding surface of the toric tool with the two meridian lines shown by dotted lines nd the curvature indicated by S and 10. Fig. 5 is an elevation of the tool with a portion in section along the line of the meridian of Fig. 4. Fig. 6 is a similar figure showing a section through a portion of the tool on the meridian line 6-6 of Fig. 4. Fig. 7 is a. section on the line 77 of Fig. 2.

The drawings herein show a stand 10 having a horizontal pan-shaped table 11 and above it a driving shaft 12 is mounted in a air of bearings 13 on the upper ends of posts 14 which extend up from the table 12, only one of which, however, is shown,

the other hearing being broken away. The shaft. is driven by a belt, not shown, operating on a pulley 15 secured to the shaft.

An emery wheel it? is mounted on the shaft 1:2 between a fixed disk 17 and a screw clamping disk 18, whereby it is held in place and it is protected by a hood 19 carried by a bracket 20 secured to the tahle 11 by bolts :21 which extend through slots 22 and permit adjustment of the hood for emery Wheels of different diameters. As stated heretofore, the diameter of the emery wheel should he. such as to give to it a circumferential curvature coinciding with the desired curvature of the tool in one meridian. say a curva turo which will give the lens surface :1 our vature of eight diopters. \Vhen it is desired to true a tool of different rurvatures the emery wheel should be removed and an other one of the proper diameter should he substituted. I1 is seldom that any change of this kind is required because as a rule there are hut few variations of curvatures in the great majority of toric tools.

toric tool 20 is shown in Figs. l, 5 and 6, that shown having a concave grinding surface with the curvature on the meridian 5-5 being 8 diopters, and the curvature on the meridian ti6 being 10 diopters.

The torio tool has a shanlt 2i which is clamped in the head, 22 of the tool holder by means of a bolt 23. The, head 22 is mounted horizontally in a frame at the upper end of an oblique bar 25 which is fulcrumed at. 22+] to an arm 27 that is piv oted h) pins 28 hetween the ears 2h and a sliding har 30. The arm I. therefore, is horizontall oseillatahle while the har 25 is vertically oscillatory and is held in adjusted position by a pawl 31 which is tulcrumed to the arm 27 hy a. pin 3:! and held h v a spring 33 which is secured to said pawl and extends under a pin 34 on the arm 22?. in engagement with the lower surface of the. har This latter surfare is provided with notches 35, one of said notches heing arrz'inged to hold the torir tool against the emery Wheel for grinding it and the other notch in position to support the tool holder in the turned-down position shown hy dotted lines in Fig. 1.

The head is longitudinally adjustahle in a sleeve 122 secured in the frame 24. The longitudinal adjustment is effected by a screw 37 screwing through an ear 137 and a set sore-w is loosely mounted in an ear '1 tending down from the head The screw is operated by a handle 39.

In order that the tool holding head 22 may be ahsolutelv in a horizontal position, during the operation of the machine. means for ad iusting and holding it in such position is provided, consisting of pivots 122"; for pivoting a sleeve 122 in the frame 21 so that it. will he oscillated. A lug 40 extends from said sleeve 122 and a set screw 41 extends through an ear 141 from the upper part of the frame 24 in engagement with the lug 40. A spiral spring 42 is located between the lug l0 and the hottom of the frame 24. By the set screw {1, therefore. the head 22 can he brought into truo horizontal position and maintained in such position regardless of the exart position of the frame :24 and bar The degree of curvature imparted to the torir tool in the horizontal meridian depends upon the relation between the position of the tool holding apparatus. with relation to the axis of the emery wheel. The degree of curvature is increased by moving the pivot of the tool holding frame to the right from the position shown in Fig. 1 and will he correspondingly increased and adjusted to the left of such position. This adjustment is etfected h v adjusting the position of the plate 80. As seen in Fig. 3. this plate is slidalile on a stationary plate 45 by means of a screw 46 and handle 47. This screw extends loosely through the turned end -18 of plate 30 and serews into a hole 49 in the plate 45. which plate is rendered secure by an integral brace 50.

The desired position of the lens holding pivot or center of oscillation is indicated and determined by a series of g aduations on the plate 549 having numerals indieating the dioptcr or degree of curvature of the tool in horizontal meridian. in cooperation with a series of graduations 56 on the plate. if; with numerals indicating! the diopters or degrees of curvature of the tool in vertical meridian. The. plate 30 is adjusted so that the numerals indirating the curvatures in the two ineridians iii register with each other. This is shown in Fig. 3. where the machine is set to operate on a toric. tool hfiving a are!" tiral curvature of it iiiopters and a :imural curvature of 8 diopters.

The invention claimed is:

l. A marhine for truing torutools and the like having curvatures in two meridian inrluding an emer wheel having a circunr ferontial eurvature the same as the desired curvature of the tool in one meridian, tool h lding moans arranged to hold the tool to the emery wheel and he osrillatahle transversely of the emery wheel in an arc agreeing with the desired curviuure of the tool in its other mer'lian, means for altering the position of the center of osveiilation of said tool holding means for changing the arc of il scillatory movruient of the tool to adapt the tool holder for tools having varying; degrees of rurrature. and graduationsfor indirating th position of said renter of osriilatiou for hulking such tools of varying curvatures.

2. A machine for trning torie tools and the like having curvature? in two miaridians,

in the other meridian.

including an emery Wheel having a circu|uslidabiy mounted on said frame to which said ferential curvature the same as the desired tool holding mechanism is pivoted so as to curvature of the tool in one meridian, tool render the tool oscillatablc transversely of holding means-arran red to hold the tool to the emery wheel and thereby adaptingthe the emery wheel and be oscillatahlc transmachine for resurfacing tools of various vcrscly of the emery wheel in an arc agreccurvatures, raduat ons being rovided for ing with the desired curvature of the tool indicating tie posit on at ivluci such plate in its other meridian, means for altering the should be set for the resurfacing of a tool. position of the center of oscillation of said 6. A machine for truing toric tools and 1!) tool holding means for changing the arc of the like having curvatures in two meridians, oscillatory movement of the tool to adapt including a frame, a shaft carried thereby, the tool holder for tools having varying ean emery wheel mounted on the shaft and grees of curvature, and two cooperatingv tool holding mechanism, a Elate slidably series of graduations for indicating the pomounted on said frame to w 15 sitions of said center of oscillation for variholding mechanism is pivoted so as to render ous tools, one of said series of graduation-s the tool oscillatabletransversely of the emrepresenting the curvature of the tool in one cry wheel and thereby adapting the ma meridian and the other series of graduachine for resurfacing tools of various curvations representing the curvature of the tool tures, a series of graduations being provided in said plate with numerals representing the 35 A machine for truing toric tools and curvature of the tool in one meridian, and the like having curvatures in two meridians, graduat ons on said frame adjacent to the including an emery wheel having a circumgraduations on said plate with numerals ferential curvature the same as the desired re resentin the curvature of the tool in the 26 curvature of the tool in one meridian, means ot er meri ian, said graduations being so for holding the tool to theemery wheel, arranged that when said plate is set with horizontal oscillatory means to which said the graduations represent ng the curvature tool holding means is pivoted so that the of the tool in the two mer dians registering tool holding means can be moved toward with each other, the machine Wlll probably 3 0. and away from theon ery wheel, said'oscilresurface the tool having such curvatures. latory means'having a center of oscillation 7. A machine for truing toric tools and which will cause the tool in the tool holder the like having curvatures in two meridians, to be oscill atable transversely of the emery including a frame, a shaft carried thereby, wheel, and means for locking and lioldin an emery wheel mounted on the shaft and tool 35 said tool holding means in said oscillatory holdingmechanism,-aplate slidably mounted 10D means in position for holding the tool on said; frame to which said tool holding against the emery wheel or throwing the mechanism is pivoted so as to render the tool holding means back out of the way for tool, oscillatable transversely of the emery replacing a tool therein. wheels-r d thereby adapting the machine for 40 4. A machine for truing toric tools and resurfacing tools of various curvatures,

the like having curvatures in two meridians, graduations bein provided for indicating including an emery wheel having a c'rcumthe position at w ich such plate should be ferential curvature the same as the .esired set or the resurfacing of a tool, and means curvature of the tool in one meridian, means for sliding said plate and holding it in its 45 for holding the tool to the emery wheel, adjusted position. no horizontal oscillatory means to which said 8. A nachine for truing torie tools and tool holding means is pivotedso that the the like having curvatures in two meridians, tool holding means can be moved toward including an emery wheel having a circumand away from the emery wheel, said oscilferential curvature the same as the desired In 50 latory means having a center of oscillation curvature of the toolin one meridian, and which will cause the tool in the tool holder means for holding the tool to the emery to be oscillatable transverselyofthe emery wheel so that it will be oscillatable trans- W eel, and a spring pawl on said 0scillaversely of said wheel and the axis of the tory means, the adjacent )ortion of said tool tool wil always be in alinement with the 65 holding means having s ioulders to be encenter of the wheel.

giiged by said pawl, one of said shoulders 9. A machine for truing toric tools and ill position to cause the pawl to hold the the'like having curvatures in two meridians, tool holding iueaiisyin working position and including an emery wheel having a circumthe other shoulder for holding the same in ferential curvature the same as the desired 5 00 non-working position. curvature of the tool in one meridian, means 5. A machine for truing toric tools and for holding the tool to the emery wheel, the like. having curvatures in two meridiand means for adjustin said tool'holder ans includinga frame, a shaft carried thereand holding it so that the axis of the tool y, an emery wheel mounted on the shaft held thereby will always lie in alinement no hge 66 and tool holding mechanism, and a plate with the center of the w 10. A machine for trumg toric tools and the like having curvatures in two meridians, including an emery wheel having a circumferential curvature the same as the desired curvature of the tool in one meridian, a tool holder for holding the tool against the emery wheel, a sleeve in which said tool holder is longitudinally movable, oscilla tory means in which said sleeve is pivoted so that it can be brought in a direction at right angles to the oscillation of said oscillatory means, adjustable means for holding said tool holder in said sleeve in the desired position for work, and means or ad justing the osition of the sleeve so that the tool hol er will hold axis in alinement with 1; wheel.

11. A machine for truing' e center of the toric tools and the like having curvatures in two meridians,

including an emery Wheel having a circum ierentlal curvature the same as thedesired curvature of the tool in one meridian, a

longitudinallv so as to the tool with its tool holder for holding the tool against the emery wheel, a sleeve in which said tool holder is lon itudinally movable, oscillatory means in w iich said sleeve is pivoted so that it can be brou ht in a direction at right angles to the oscillation of said oscillatory means, a setting screw operatively connecting said oscillatory means and said tool for adjusting the tool holder work, a lug extending laterall from sai tool holder, a screw in said oseil atory means for enga ing said lugand oscillating said sleeve to ring the tool holder in such position that the axis of the tool will be in 'alinement with the center of the wheel, and a spring acting between said oscillator means and said lug for 006 erating wit said screw, substantially as own.

In witness whereof I have hereunto affixed my signature.

JOHN HARVEY PEARSEN.

hold the tool to its Correction in Letters Patent Nb. 1287,09!

It is hereby certified that the name. of the patentee in Letters Patent No.

1,287,091, granted December 10, 1918, or an improvement in Marhines for Truing 'Ioric Tools, was erroneously written and printed a "J h H Penn sen, whereas said name should have been written and printed as J h Hwvey Pearson; and that the said Letters Patent should he read with this correcuqn therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of January, A. 1)., 1919,

[ F. w. u. CLAY,

Acting Commissioner of Patents. CL 

